Facile preparation of reduced graphene oxide for removing tetracycline from water: Kinetics and thermodynamics studies

In this study, reduced graphene oxide (rGO) was successfully produced from graphite precursor by chemical oxidation and exfoliation processes that were followed by a reduction process under mild conditions. SEM/EDX, XRD, FT-IR, BET, pH(pzc) were conducted to characterize the as-synthesized materials. Impacts of different factors such as contact time, temperature, pH of the solution, adsorbent load, and tetracycline (TC) concentration on TC removal efficiency were examined. Furthermore, the adsorption kinetics, thermodynamics, and isotherms were also investigated. As the result, the adsorption process of TC onto rGO was spontaneous, endothermic, and governed by both physisorption and chemisorption. The maximum uptake calculated from the Langmuir isotherm model was 58.03 mg/g. rGO material could be regenerated by using methanol and diluted NaOH solutions. The findings in this work provided complete data on the TC adsorption process onto rGO and the process of the recovery and reuse of rGO.

Automated summary

This study successfully produced rGO material and characterized it comprehensively, while studying the adsorption properties of TC on it, including adsorption kinetics, thermodynamics, and adsorption isotherms. The experimental results showed that the adsorption of TC on rGO is spontaneous, endothermic, and governed by both physisorption and chemisorption.